Direct Drive And Belt Driven Fans

You have a fan a motor and maybe a coupling.

Direct drive and belt driven fans.

When compared to belt drive fans which require belts sheaves and bushings direct drive is just plain simpler and maintenance folks tend to lean toward direct drive for daily maintenance. On a direct drive fan as implied by the name the fan propeller is connected directly to the shaft of the motor. On both direct drive and belt drive fans the motor has two bearings. Direct drive fans require fewer parts and thus usually less maintenance.

Unlike the belt driven fans in case of a direct drive fan there is lesser energy loss. While both belt and direct drive fans have been around for a long time the mainstay fan for most industrial fan applications under 250 hp has been the belt drive fan. Belt drive fans have two additional bearings. Unlike belt driven fans there s less energy loss because there s a reduced amount of friction as the fan operates.

Where on a belt drive fan the fan motor shaft has a pulley connected by a belt to a second pulley. Greater efficiency is the biggest pro of direct drive fan configurations. More often than not the maintenance cost of this kind of fan is also comparatively lower. Direct drive fans should be designed for acceptable bearing life.

The second pulley is connected to a shaft that drives the fan propeller. With the growing acceptance and affordability of vfd motor controllers direct drive fans are increasingly finding their way into mainstream industrial fan applications. This is because of the fact that the amount of friction is greatly reduced in case of this fan when the fan is operating. The two bearings on direct drive fan motors which are 7 horsepower and larger are typically regreaseable.